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Kim HG, Shin J, Choi YH. Human-Unrecognizable Differential Private Noised Image Generation Method. SENSORS (BASEL, SWITZERLAND) 2024; 24:3166. [PMID: 38794019 PMCID: PMC11125371 DOI: 10.3390/s24103166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/29/2024] [Accepted: 05/07/2024] [Indexed: 05/26/2024]
Abstract
Differential privacy has emerged as a practical technique for privacy-preserving deep learning. However, recent studies on privacy attacks have demonstrated vulnerabilities in the existing differential privacy implementations for deep models. While encryption-based methods offer robust security, their computational overheads are often prohibitive. To address these challenges, we propose a novel differential privacy-based image generation method. Our approach employs two distinct noise types: one makes the image unrecognizable to humans, preserving privacy during transmission, while the other maintains features essential for machine learning analysis. This allows the deep learning service to provide accurate results, without compromising data privacy. We demonstrate the feasibility of our method on the CIFAR100 dataset, which offers a realistic complexity for evaluation.
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Ahn S, Ahn S, Jang H, Eom K, Kim YJ, Hwang JE, Chung JI, Park JY, Nam S, Choi YH, Joung H. Validation of resonance Raman spectroscopy-measured skin carotenoid status as a biomarker for fruit and vegetable intake in Korean adults. Br J Nutr 2023; 130:1993-2001. [PMID: 37184085 DOI: 10.1017/s0007114523001058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Blood carotenoid concentration measurement is considered the gold standard for fruit and vegetable (F&V) intake estimation; however, this method is invasive and expensive. Recently, skin carotenoid status (SCS) measured by optical sensors has been evaluated as a promising parameter for F&V intake estimation. In this cross-sectional study, we aimed to validate the utility of resonance Raman spectroscopy (RRS)-assessed SCS as a biomarker of F&V intake in Korean adults. We used data from 108 participants aged 20-69 years who completed SCS measurements, blood collection and 3-d dietary recordings. Serum carotenoid concentrations were quantified using HPLC, and dietary carotenoid and F&V intakes were estimated via 3-d dietary records using a carotenoid database for common Korean foods. The correlations of the SCS with serum carotenoid concentrations, dietary carotenoid intake and F&V intake were examined to assess SCS validity. SCS was positively correlated with total serum carotenoid concentration (r = 0·52, 95 % CI = 0·36, 0·64, P < 0·001), serum β-carotene concentration (r = 0·60, 95 % CI = 0·47, 0·71, P < 0·001), total carotenoid intake (r = 0·20, 95 % CI = 0·01, 0·37, P = 0·04), β-carotene intake (r = 0·30, 95 % CI = 0·11, 0·46, P = 0·002) and F&V intake (r = 0·40, 95 % CI = 0·23, 0·55, P < 0·001). These results suggest that SCS can be a valid biomarker of F&V intake in Korean adults.
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Hwang SJ, Utaliyeva A, Kim JS, Choi YH. Bypassing Heaven's Gate Technique Using Black-Box Testing. SENSORS (BASEL, SWITZERLAND) 2023; 23:9417. [PMID: 38067790 PMCID: PMC10708677 DOI: 10.3390/s23239417] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/18/2023] [Accepted: 11/24/2023] [Indexed: 07/04/2024]
Abstract
In recent years, the number and sophistication of malware attacks on computer systems have increased significantly. One technique employed by malware authors to evade detection and analysis, known as Heaven's Gate, enables 64-bit code to run within a 32-bit process. Heaven's Gate exploits a feature in the operating system that allows the transition from a 32-bit mode to a 64-bit mode during execution, enabling the malware to evade detection by security software designed to monitor only 32-bit processes. Heaven's Gate poses significant challenges for existing security tools, including dynamic binary instrumentation (DBI) tools, widely used for program analysis, unpacking, and de-virtualization. In this paper, we provide a comprehensive analysis of the Heaven's Gate technique. We also propose a novel approach to bypass the Heaven's Gate technique using black-box testing. Our experimental results show that the proposed approach effectively bypasses and prevents the Heaven's Gate technique and strengthens the capabilities of DBI tools in combating advanced malware threats.
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Park JH, Moon HS, Jung HI, Hwang J, Choi YH, Kim JE. Deep learning and clustering approaches for dental implant size classification based on periapical radiographs. Sci Rep 2023; 13:16856. [PMID: 37803022 PMCID: PMC10558577 DOI: 10.1038/s41598-023-42385-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 09/09/2023] [Indexed: 10/08/2023] Open
Abstract
This study investigated two artificial intelligence (AI) methods for automatically classifying dental implant diameter and length based on periapical radiographs. The first method, deep learning (DL), involved utilizing the pre-trained VGG16 model and adjusting the fine-tuning degree to analyze image data obtained from periapical radiographs. The second method, clustering analysis, was accomplished by analyzing the implant-specific feature vector derived from three key points coordinates of the dental implant using the k-means++ algorithm and adjusting the weight of the feature vector. DL and clustering model classified dental implant size into nine groups. The performance metrics of AI models were accuracy, sensitivity, specificity, F1-score, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC-ROC). The final DL model yielded performances above 0.994, 0.950, 0.994, 0.974, 0.952, 0.994, and 0.975, respectively, and the final clustering model yielded performances above 0.983, 0.900, 0.988, 0.923, 0.909, 0.988, and 0.947, respectively. When comparing the AI model before tuning and the final AI model, statistically significant performance improvements were observed in six out of nine groups for DL models and four out of nine groups for clustering models based on AUC-ROC. Two AI models showed reliable classification performances. For clinical applications, AI models require validation on various multicenter data.
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Kim TJ, Pyo JH, Lee H, Choi SC, Min YW, Min BH, Lee JH, Rhee PL, Song M, Choi YH, Kim JJ. Outcomes of Endoscopic Resection for Early Gastric Cancer in Very Elderly Patients: A Nationwide Population-Based Study. Gut Liver 2023; 17:529-536. [PMID: 36578192 PMCID: PMC10352067 DOI: 10.5009/gnl210430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 08/20/2022] [Accepted: 08/26/2022] [Indexed: 12/30/2022] Open
Abstract
Background/Aims Few studies have investigated the long-term outcomes of endoscopic resection for early gastric cancer (EGC) in very elderly patients. The aim of this study was to determine the appropriate treatment strategy and identify the risk factors for mortality in these patients. Methods Patients with EGC who underwent endoscopic resection from 2006 to 2017 were identified using National Health Insurance Data and divided into three age groups: very elderly (≥85 years), elderly (65 to 84 years), and non-elderly (≤64 years). Their long- and short-term outcomes were compared in the three age groups, and the survival in the groups was compared with that in the control group, matched by age and sex. We also evaluated the risk factors for long- and short-term outcomes. Results A total of 8,426 patients were included in our study: 118 very elderly, 4,583 elderly, and 3,725 non-elderly. The overall survival and cancer-specific survival rates were significantly lower in the very elderly group than in the elderly and the non-elderly groups. Congestive heart failure was negatively associated with cancer-specific survival. A significantly decreased risk for mortality was observed in all groups (p<0.001). The very elderly group had significantly higher readmission and mortality rates within 3 months of endoscopic resection than the non-elderly and elderly groups. Furthermore, the cerebrovascular disease was associated with mortality within 3 months after endoscopic resection. Conclusions Endoscopic resection for EGC can be helpful for very elderly patients, and it may play a role in achieving overall survival comparable to that of the control group.
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Lee D, Cho S, Park C, Park KR, Lee J, Nam J, Ahn K, Park C, Jeon K, Yuh H, Choi W, Lim CH, Kwon T, Min YH, Joo M, Choi YH, Lee JS, Kim C, Kwon S. Fluidic self-assembly for MicroLED displays by controlled viscosity. Nature 2023:10.1038/s41586-023-06167-5. [PMID: 37438523 DOI: 10.1038/s41586-023-06167-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/04/2023] [Indexed: 07/14/2023]
Abstract
Displays in which arrays of microscopic 'particles', or chiplets, of inorganic light-emitting diodes (LEDs) constitute the pixels, termed MicroLED displays, have received considerable attention1,2 because they can potentially outperform commercially available displays based on organic LEDs3,4 in terms of power consumption, colour saturation, brightness and stability and without image burn-in issues1,2,5-7. To manufacture these displays, LED chiplets must be epitaxially grown on separate wafers for maximum device performance and then transferred onto the display substrate. Given that the number of LEDs needed for transfer is tremendous-for example, more than 24 million chiplets smaller than 100 μm are required for a 50-inch, ultra-high-definition display-a technique capable of assembling tens of millions of individual LEDs at low cost and high throughput is needed to commercialize MicroLED displays. Here we demonstrate a MicroLED lighting panel consisting of more than 19,000 disk-shaped GaN chiplets, 45 μm in diameter and 5 μm in thickness, assembled in 60 s by a simple agitation-based, surface-tension-driven fluidic self-assembly (FSA) technique with a yield of 99.88%. The creation of this level of large-scale, high-yield FSA of sub-100-μm chiplets was considered a significant challenge because of the low inertia of the chiplets. Our key finding in overcoming this difficulty is that the addition of a small amount of poloxamer to the assembly solution increases its viscosity which, in turn, increases liquid-to-chiplet momentum transfer. Our results represent significant progress towards the ultimate goal of low-cost, high-throughput manufacture of full-colour MicroLED displays by FSA.
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Choi YH, Kim JS, Byun G. Source localization based on steered frequency-wavenumber analysis for sparse array. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2023; 153:3065. [PMID: 37222575 DOI: 10.1121/10.0019552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/06/2023] [Indexed: 05/25/2023]
Abstract
When using a sparse array, locating the target signal of a high-frequency component is difficult. Although forecasting the direction in a sparse situation is challenging, the frequency-wavenumber (f-k) spectrum can simultaneously determine the direction and frequency of the analyzed signal. The striation of the f-k spectrum shifts along the wavenumber axis in a sparse situation, which reduces the spatial resolution required to determine the target's direction using the f-k spectrum. In this study, f-k spectra of a high-frequency signal were used for near-field source localization. Snapping shrimp sounds (5-24 kHz) from SAVEX15 (a shallow-water acoustic variability experiment conducted in May 2015) were used as the data source, and a simulation was used to evaluate the proposed method. Beam steering was performed before creating the f-k spectrum to improve spatial resolution. We found that the spatial resolution was improved, and the location of the sound source could be determined when a signal with beam steering was utilized. The shrimp sound from SAVEX15, a near-field broadband signal, was used to determine the shrimp's location (range, 38 m; depth, 100 m) and the tilt of the vertical line array. These results suggest that the proposed analysis helps to accurately estimate the location of sound source.
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Chang W, Kim J, Kim M, Lee MW, Lim CH, Kim G, Hwang S, Chang J, Min YH, Jeon K, Kim S, Choi YH, Lee JS. Concurrent self-assembly of RGB microLEDs for next-generation displays. Nature 2023; 617:287-291. [PMID: 37138079 DOI: 10.1038/s41586-023-05889-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 02/24/2023] [Indexed: 05/05/2023]
Abstract
MicroLED displays have been in the spotlight as the next-generation displays owing to their various advantages, including long lifetime and high brightness compared with organic light-emitting diode (OLED) displays. As a result, microLED technology1,2 is being commercialized for large-screen displays such as digital signage and active R&D programmes are being carried out for other applications, such as augmented reality3, flexible displays4 and biological imaging5. However, substantial obstacles in transfer technology, namely, high throughput, high yield and production scalability up to Generation 10+ (2,940 × 3,370 mm2) glass sizes, need to be overcome so that microLEDs can enter mainstream product markets and compete with liquid-crystal displays and OLED displays. Here we present a new transfer method based on fluidic self-assembly (FSA) technology, named magnetic-force-assisted dielectrophoretic self-assembly technology (MDSAT), which combines magnetic and dielectrophoresis (DEP) forces to achieve a simultaneous red, green and blue (RGB) LED transfer yield of 99.99% within 15 min. By embedding nickel, a ferromagnetic material, in the microLEDs, their movements were controlled by using magnets, and by applying localized DEP force centred around the receptor holes, these microLEDs were effectively captured and assembled in the receptor site. Furthermore, concurrent assembly of RGB LEDs were demonstrated through shape matching between microLEDs and receptors. Finally, a light-emitting panel was fabricated, showing damage-free transfer characteristics and uniform RGB electroluminescence emission, demonstrating our MDSAT method to be an excellent transfer technology candidate for high-volume production of mainstream commercial products.
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Utaliyeva A, Shin J, Choi YH. Task-Specific Adaptive Differential Privacy Method for Structured Data. SENSORS (BASEL, SWITZERLAND) 2023; 23:1980. [PMID: 36850576 PMCID: PMC9966464 DOI: 10.3390/s23041980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Data are needed to train machine learning (ML) algorithms, and in many cases often include private datasets that contain sensitive information. To preserve the privacy of data used while training ML algorithms, computer scientists have widely deployed anonymization techniques. These anonymization techniques have been widely used but are not foolproof. Many studies showed that ML models using anonymization techniques are vulnerable to various privacy attacks willing to expose sensitive information. As a privacy-preserving machine learning (PPML) technique that protects private data with sensitive information in ML, we propose a new task-specific adaptive differential privacy (DP) technique for structured data. The main idea of the proposed DP method is to adaptively calibrate the amount and distribution of random noise applied to each attribute according to the feature importance for the specific tasks of ML models and different types of data. From experimental results under various datasets, tasks of ML models, different DP mechanisms, and so on, we evaluate the effectiveness of the proposed task-specific adaptive DP method. Thus, we show that the proposed task-specific adaptive DP technique satisfies the model-agnostic property to be applied to a wide range of ML tasks and various types of data while resolving the privacy-utility trade-off problem.
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Jae SY, Kim HJ, Lee KH, Kunutsor SK, Heffernan KS, Choi YH, Kang M. Joint Associations of Obesity and Cardiorespiratory Fitness With Coronary Artery Calcium Composition: IS THERE EVIDENCE FOR FAT-BUT-FIT? J Cardiopulm Rehabil Prev 2022; 42:202-207. [PMID: 35135962 DOI: 10.1097/hcr.0000000000000631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION The purpose of this study was to examine the individual and joint associations of obesity and cardiorespiratory fitness (CRF) with indices of coronary artery calcification (CAC) in 2090 middle-aged men. METHODS Obesity was defined as a body mass index (BMI) ≥25 kg/m2 and a waist circumference (WC) ≥90 cm. Cardiorespiratory fitness was operationally defined as peak oxygen uptake (V˙o2peak) directly measured using gas analysis. Participants were then divided into unfit and fit categories based on age-specific V˙o2peak percentiles. Agatston scores >100 and volume and density scores >75th percentile were defined as indices of CAC, signifying advanced subclinical atherosclerosis. RESULTS Obese men had increased CAC Agatston, volume, and density scores, while higher CRF was associated with lower Agatston and volume scores after adjusting for potential confounders. In the joint analysis, unfit-obese men had higher CAC Agatston and CAC volume. The fit-obesity category was not associated with CAC Agatston (OR = 0.91: 95% CI, 0.66-1.25, for BMI and OR = 1.21: 95% CI, 0.86-1.70, for WC) and CAC volume (OR = 1.14: 95% CI, 0.85-1.53, for BMI and OR = 1.23: 95% CI, 0.90-1.69, for WC), which were similar to estimates for the fit-normal weight category. CONCLUSIONS These findings demonstrate that while obesity is positively associated with the prevalence of moderate to severe CAC scores, CRF is inversely associated with the prevalence of moderate to severe CAC scores. Additionally, the combination of being fit and obese was not associated with CAC scores, which could potentially reinforce the fat-but-fit paradigm.
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Park D, Cho SJ, Kim K, Woo H, Kim JE, Lee JY, Koh J, Lee J, Choi JS, Chang DK, Choi YH, Chung JI, Cha WC, Jeong OS, Jekal SY, Kang M. Prediction Algorithms for Blood Pressure Based on Pulse Wave Velocity Using Health Checkup Data in Healthy Korean Men: Algorithm Development and Validation. JMIR Med Inform 2021; 9:e29212. [PMID: 34889753 PMCID: PMC8701706 DOI: 10.2196/29212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/06/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Pulse transit time and pulse wave velocity (PWV) are related to blood pressure (BP), and there were continuous attempts to use these to predict BP through wearable devices. However, previous studies were conducted on a small scale and could not confirm the relative importance of each variable in predicting BP. OBJECTIVE This study aims to predict systolic blood pressure and diastolic blood pressure based on PWV and to evaluate the relative importance of each clinical variable used in BP prediction models. METHODS This study was conducted on 1362 healthy men older than 18 years who visited the Samsung Medical Center. The systolic blood pressure and diastolic blood pressure were estimated using the multiple linear regression method. Models were divided into two groups based on age: younger than 60 years and 60 years or older; 200 seeds were repeated in consideration of partition bias. Mean of error, absolute error, and root mean square error were used as performance metrics. RESULTS The model divided into two age groups (younger than 60 years and 60 years and older) performed better than the model without division. The performance difference between the model using only three variables (PWV, BMI, age) and the model using 17 variables was not significant. Our final model using PWV, BMI, and age met the criteria presented by the American Association for the Advancement of Medical Instrumentation. The prediction errors were within the range of about 9 to 12 mmHg that can occur with a gold standard mercury sphygmomanometer. CONCLUSIONS Dividing age based on the age of 60 years showed better BP prediction performance, and it could show good performance even if only PWV, BMI, and age variables were included. Our final model with the minimal number of variables (PWB, BMI, age) would be efficient and feasible for predicting BP.
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Goszczynski DE, Tinetti PS, Choi YH, Hinrichs K, Ross PJ. Genome activation in equine in vitro-produced embryos. Biol Reprod 2021; 106:66-82. [PMID: 34515744 DOI: 10.1093/biolre/ioab173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/17/2021] [Accepted: 09/07/2021] [Indexed: 11/13/2022] Open
Abstract
Embryonic genome activation is a critical event in embryo development, in which the transcriptional program of the embryo is initiated. The timing and regulation of this process are species-specific. In vitro embryo production is becoming an important clinical and research tool in the horse; however, very little is known about genome activation in this species. The objective of this work was to identify the timing of genome activation, and the transcriptional networks involved, in in vitro-produced horse embryos. RNA-Seq was performed on oocytes and embryos at eight stages of development (MII, zygote, 2-cell, 4-cell, 8-cell, 16-cell, morula, blastocyst; n = 6 per stage, 2 from each of 3 mares). Transcription of seven genes was initiated at the 2-cell stage. The first substantial increase in gene expression occurred at the 4-cell stage (minor activation), followed by massive gene upregulation and downregulation at the 8-cell stage (major activation). An increase in intronic nucleotides, indicative of transcription initiation, was also observed at the 4-cell stage. Co-expression network analyses identified groups of genes that appeared to be regulated by common mechanisms. Investigation of hub genes and binding motifs enriched in the promoters of co-expressed genes implicated several transcription factors. This work represents, to the best of our knowledge, the first genomic evaluation of embryonic genome activation in horse embryos.
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Goszczynski DE, Tinetti PS, Choi YH, Ross PJ, Hinrichs K. Allele-specific expression analysis reveals conserved and unique features of preimplantation development in equine ICSI embryos. Biol Reprod 2021; 105:1416-1426. [PMID: 34515759 DOI: 10.1093/biolre/ioab174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/17/2021] [Accepted: 09/10/2021] [Indexed: 12/30/2022] Open
Abstract
Embryonic genome activation and dosage compensation are major genetic events in early development. Combined analysis of single embryo RNA-seq data and parental genome sequencing was used to evaluate parental contributions to early development and investigate X-chromosome dynamics. In addition, we evaluated dimorphism in gene expression between male and female embryos. Evaluation of parent-specific gene expression revealed a minor increase in paternal expression at the 4-cell stage that increased at the 8-cell stage. We also detected eight genes with allelic expression bias that may have an important role in early development, notably NANOGNB. The main actor in X-chromosome inactivation, XIST, was significantly upregulated at the 8-cell, morula, and blastocyst stages in female embryos, with high expression at the latter. Sexual dimorphism in gene expression was identified at all stages, with strong representation of the X-chromosome in females from the 16-cell to the blastocyst stage. Female embryos showed biparental X-chromosome expression at all stages after the 4-cell stage, demonstrating the absence of imprinted X-inactivation at the embryo level. The analysis of gene dosage showed incomplete dosage compensation (0.5 < X:A < 1) in MII oocytes and embryos up to the 4-cell stage, an increase of the X:A ratio at the 16-cell and morula stages after genome activation, and a decrease of the X:A ratio at the blastocyst stage, which might be associated with the beginning of X-chromosome inactivation. This study represents the first critical analysis of parent- and sex-specific gene expression in early equine embryos produced in vitro.
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Kang D, Kim JY, Kim JY, Mun HS, Yoon SJ, Lee J, Han G, Im YH, Shin SY, Lee SK, Yu JH, Lee KH, Kim M, Park D, Choi YH, Jeong OS, Lee JH, Jekal SY, Choi JS, Guallar E, Chang Y, Ryu S, Cho J, Kang M. The Relationship Between Breast Density Change During Menopause and the Risk of Breast Cancer in Korean Women. Cancer Prev Res (Phila) 2021; 14:1119-1128. [PMID: 34507971 DOI: 10.1158/1940-6207.capr-20-0542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/14/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND The aim of this study was to investigate the relationship between changes in breast density during menopause and breast cancer risk. METHODS This study was a retrospective, longitudinal cohort study for women over 30 years of age who had undergone breast mammography serially at baseline and postmenopause during regular health checkups at Samsung Medical Center. None of the participants had been diagnosed with breast cancer at baseline. Mammographic breast density was measured using the American College of Radiology Breast Imaging Reporting and Data System. RESULTS During 18,615 person-years of follow-up (median follow-up 4.8 years; interquartile range 2.8-7.5 years), 45 participants were diagnosed with breast cancer. The prevalence of dense breasts was higher in those who were younger, underweight, had low parity or using contraceptives. The cumulative incidence of breast cancer increased 4 years after menopause in participants, and the consistently extremely dense group had a significantly higher cumulative incidence (CI) of breast cancer compared with other groups [CI of extremely dense vs. others (incidence rate per 100,000 person-years): 375 vs. 203, P < 0.01]. CONCLUSION Korean women whose breast density was extremely dense before menopause and who maintained this density after menopause were at two-fold greater risk of breast cancer. PREVENTION RELEVANCE Extremely dense breast density that is maintained persistently from premenopause to postmenopause increases risk of breast cancer two fold in Korean women. Therefore, women having risk factors should receive mammography frequently and if persistently extremely dense breast had been detected, additional modalities of BC screening could be considered.
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Pyo JH, Kim TJ, Lee H, Choi SC, Cho SJ, Choi YH, Min YW, Min BH, Lee JH, Kang M, Lee YC, Kim JJ. Proton pump inhibitors use and the risk of fatty liver disease: A nationwide cohort study. J Gastroenterol Hepatol 2021; 36:1235-1243. [PMID: 32886822 DOI: 10.1111/jgh.15236] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 08/03/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND AIM Proton pump inhibitor (PPI)-induced hypochondria can change the composition of the gut microbiota, inducing overgrowth of small bowel bacteria, which has been suggested to promote the development of fatty liver disease through the gut-liver axis. In this study, we aimed to investigate the association between PPI use and the risk of fatty liver disease. METHODS A retrospective cohort study was conducted using the Korean National Health Insurance Service-National Sample Cohort, a nationwide population-based representative sample, from January 1, 2002, to December 31, 2015. PPI use was identified from treatment claims and considered as a time-varying variable. RESULTS During 1 463 556 person-years of follow-up, 75 727 patients had at least one PPI prescription, and 3735 patients developed fatty liver disease. The hazard ratio for fatty liver disease comparing PPI users with non-PPI users was 1.68 (95% confidence interval, 1.61-1.75). When adjusted for multiple confounders, including age, sex, body mass index, smoking, alcohol intake, exercise, income level, and comorbidities, the association was still significant (hazard ratio, 1.50; 95% confidence interval, 1.44-1.57). After considering the amounts of PPIs stratified by cumulative defined daily dose, the dose-response effect was observed until 180 days. Subgroup analysis also revealed that PPI use was correlated to an increased risk of fatty liver disease. CONCLUSIONS This current national wide cohort study suggests that PPI use was associated with an increased risk of fatty liver disease compared with non-use of PPIs. Clinicians should consider fatty liver as a potential risk when prescribing PPI.
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Jung BO, Lee W, Kim J, Choi M, Shin HY, Joo M, Jung S, Choi YH, Kim MJ. Enhancement in external quantum efficiency of AlGaInP red μ-LED using chemical solution treatment process. Sci Rep 2021; 11:4535. [PMID: 33633206 PMCID: PMC7907351 DOI: 10.1038/s41598-021-83933-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 02/02/2021] [Indexed: 11/30/2022] Open
Abstract
To investigate the effects of their surface recovery and optical properties, extremely small sized (12 µm × 12 µm mesa area) red AlGaInP micro light emitting diodes (\documentclass[12pt]{minimal}
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\begin{document}$$\upmu$$\end{document}μ-LED at low and high injection current regions have been improved by 35.48% and 12.86%, respectively. The different phenomena of EQEs have a complex relationship between the suppression of non-radiative recombination originating from the etching damage of the surface and the improvement of light extraction of the sidewalls. The constant enhancement of EQE at a high injection current it is attributed to the expansion of the active region’s sidewall surface area by the selective etching of AlInP layers. The improved EQE at a low injection current is related to the minimization of the surface recombination caused by plasma damage from the surface. High-resolution transmission electron microscopy (HR-TEM) revealed physical defects on the sidewall surface, such as plasma-induced lattice disorder and impurity contamination damage, were eliminated using chemical treatment. This study suggests that chemical surface treatment using diluted HF acid can be an effective method for enhancing the \documentclass[12pt]{minimal}
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\begin{document}$$\upmu$$\end{document}μ-LED performance.
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Roh YH, Yoo SJ, Choi YH, Yang HC, Nam KW. Effects of Inflammatory Disease on Clinical Progression and Treatment of Ischiogluteal Bursitis: A Retrospective Observational Study. Malays Orthop J 2021; 14:32-41. [PMID: 33403060 PMCID: PMC7752025 DOI: 10.5704/moj.2011.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Introduction: The symptoms of Ischiogluteal Bursitis (IGB) are often nonspecific and atypical, and its diagnosis is more challenging. Moreover, it is difficult to predict cases of chronic progression or poor treatment response. Therefore, the aim of this study was to investigate the clinical course of IGB patients and identify factors that are predictive of failure of conservative treatment. Materials and Methods: Our study consisted of IGB patients diagnosed between 2010 March and 2016 December who had been followed-up for at least one year. Structured questionnaires and medical records were reviewed to analyse demographic characteristics, lifestyle patterns, blood tests, and imaging studies. We categorized the cases into two groups based on the response to conservative treatment and the need for surgical intervention. Results: The most common initial chief symptoms were buttock pains in 24 patients (37.5%). Physical examinations showed the tenderness of ischial tuberosity area in 59 (92.2%) patients, but no specific findings were confirmed in 5 patients (7.8%). 51 patients (79.7%) responded well to the conservative management, 11 patients (17.2%) needed injection, and 2 patients (3.1%) had surgical treatment performed due to continuous recurrence. There was no difference in demographic and blood lab data between the two groups. However, the incidence of inflammatory diseases (response group: 10.3% vs non-response group: 66.7%, p=0.004) was significantly different between the two groups. Conclusion: The diagnosis of IGB can be missed due to variations in clinical symptoms, and cautions should be exercised in patients with inflammatory diseases as conservative treatment is less effective in them, leading to chronic progression of IGB.
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Ko D, Choi SH, Ahn S, Choi YH. Robust Indoor Localization Methods Using Random Forest-Based Filter against MAC Spoofing Attack. SENSORS (BASEL, SWITZERLAND) 2020; 20:s20236756. [PMID: 33255976 PMCID: PMC7730504 DOI: 10.3390/s20236756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/09/2020] [Accepted: 11/23/2020] [Indexed: 06/12/2023]
Abstract
With the development of wireless networks and mobile devices, interest on indoor localization systems (ILSs) has increased. In particular, Wi-Fi-based ILSs are widely used because of the good prediction accuracy without additional hardware. However, as the prediction accuracy decreases in environments with natural noise, some studies were conducted to remove it. So far, two representative methods, i.e., the filtering-based method and deep learning-based method, have shown a significant effect in removing natural noise. However, the prediction accuracy of these methods severely decreased under artificial noise caused by adversaries. In this paper, we introduce a new media access control (MAC) spoofing attack scenario injecting artificial noise, where the prediction accuracy of Wi-Fi-based indoor localization system significantly decreases. We also propose a new deep learning-based indoor localization method using random forest(RF)-filter to provide the good prediction accuracy under the new MAC spoofing attack scenario. From the experimental results, we show that the proposed indoor localization method provides much higher prediction accuracy than the previous methods in environments with artificial noise.
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Nkenyereye L, Adhi Tama B, Shahzad MK, Choi YH. Secure and Blockchain-Based Emergency Driven Message Protocol for 5G Enabled Vehicular Edge Computing. SENSORS 2019; 20:s20010154. [PMID: 31881766 PMCID: PMC6983214 DOI: 10.3390/s20010154] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/08/2019] [Accepted: 12/23/2019] [Indexed: 11/16/2022]
Abstract
Basic safety message (BSM) are messages that contain core elements of a vehicle such as vehicle’s size, position, speed, acceleration and others. BSM are lightweight messages that can be regularly broadcast by the vehicles to enable a variety of applications. On the other hand, event-driven message (EDM) are messages generated at the time of occurrence such as accidents or roads sliding and can contain much more heavy elements including pictures, audio or videos. Security, architecture and communication solutions for BSM use cases have been largely documented on in the literature contrary to EDM due to several concerns such as the variant size of EDM, the appropriate architecture along with latency, privacy and security. In this paper, we propose a secure and blockchain based EDM protocol for 5G enabled vehicular edge computing. To offer scalability and latency for the proposed scenario, we adopt a 5G cellular architecture due to its projected features compared to 4G tong-term evaluation (LTE) for vehicular communications. We consider edge computing to provide local processing of EDM that can improve the response time of public agencies (ambulances or rescue teams) that may intervene to the scene. We make use of lightweight multi-receiver signcryption scheme without pairing that offers low time consuming operations, security, privacy and access control. EDM records need to be kept into a distributed system which can guarantee reliability and auditability of EDM. To achieve this, we construct a private blockchain based on the edge nodes to store EDM records. The performance analysis of the proposed protocol confirms its efficiency.
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Nkenyereye L, Nkenyereye L, Islam SMR, Choi YH, Bilal M, Jang JW. Software-Defined Network-Based Vehicular Networks: A Position Paper on Their Modeling and Implementation. SENSORS 2019; 19:s19173788. [PMID: 31480479 PMCID: PMC6749579 DOI: 10.3390/s19173788] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022]
Abstract
There is a strong devotion in the automotive industry to be part of a wider progression towards the Fifth Generation (5G) era. In-vehicle integration costs between cellular and vehicle-to-vehicle networks using Dedicated Short Range Communication could be avoided by adopting Cellular Vehicle-to-Everything (C-V2X) technology with the possibility to re-use the existing mobile network infrastructure. More and more, with the emergence of Software Defined Networks, the flexibility and the programmability of the network have not only impacted the design of new vehicular network architectures but also the implementation of V2X services in future intelligent transportation systems. In this paper, we define the concepts that help evaluate software-defined-based vehicular network systems in the literature based on their modeling and implementation schemes. We first overview the current studies available in the literature on C-V2X technology in support of V2X applications. We then present the different architectures and their underlying system models for LTE-V2X communications. We later describe the key ideas of software-defined networks and their concepts for V2X services. Lastly, we provide a comparative analysis of existing SDN-based vehicular network system grouped according to their modeling and simulation concepts. We provide a discussion and highlight vehicular ad-hoc networks' challenges handled by SDN-based vehicular networks.
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Shin J, Ko H, Choi YH, Choi I, Song YM. Risk of comorbid cardiovascular disease in Korean long-term cancer survivors. Eur J Cancer Care (Engl) 2019; 28:e13151. [PMID: 31433537 DOI: 10.1111/ecc.13151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 03/11/2019] [Accepted: 03/25/2019] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cardiovascular disease (CVD) is a common cause of death in cancer survivors. We evaluated the risk of comorbid CVD in long-term cancer survivors according to specific cancer site. METHODS Study subjects included 47,171 Koreans aged over 40 years who visited a health promotion centre between 2010 and 2012. Information on CVD and cancer was obtained from self-report. Comorbid CVD was defined as stroke, myocardial infarction or angina pectoris. The risk of comorbid CVD in survivors was compared with that in non-cancer subjects using multiple logistic regression analysis. RESULTS Among cancer survivors (n = 3,753), 330 events of CVD were reported. Age- and sex-adjusted analysis showed that odds ratio (OR) for comorbid CVD in survivors was 1.52 (95% confidence interval: 1.34-1.72) compared to non-cancer subjects (n = 43,418). After adjusting for health-related behaviour and medical history, only lung cancer survivors had 2.44 (1.01-5.89)-fold higher OR for CVD. In stratified analysis, significantly higher OR for CVD was evident in lung cancer survivors with hypertension who did not perform regular physical exercise. CONCLUSIONS Adult cancer survivors may have an increased risk of comorbid CVD that might be mediated in part by known cardiovascular risk factors depending on the specific cancer site.
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Pyo JH, Lee H, Choi SC, Cho SJ, Choi YH, Min YW, Min BH, Lee JH, Yoo H, Kim K, Kim JJ. Lack of Association between Past Helicobacter pylori Infection and Diabetes: A Two-Cohort Study. Nutrients 2019; 11:nu11081874. [PMID: 31409000 PMCID: PMC6723734 DOI: 10.3390/nu11081874] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 02/07/2023] Open
Abstract
Helicobacter pylori (H. pylori) may be involved in diabetes and other insulin-related processes. This study aimed to investigate the associations between H. pylori infection and the risks of type 2 diabetes, impaired glucose tolerance (IGT), diabetic nephropathy, and poor glycemic control. We retrospectively evaluated 16,091 subjects without diabetes at baseline who underwent repeated health examinations. Subjects were categorized according to whether they were seropositive and seronegative for H. pylori infection. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazard models. The serological results were validated using an independent cohort (n = 42,351) based on a histological diagnosis of H. pylori infection. During 108,614 person-years of follow-up, 1338 subjects (8.3%) developed newly diagnosed diabetes, although the cumulative incidence of diabetes was not significantly related to serological H. pylori status. The multivariate Cox proportional-hazards regression models revealed that H. pylori seropositivity was not significantly associated with diabetes (HR: 1.01, 95% CI: 0.88–1.16; p = 0.854), IGT (HR: 0.98, 95% CI: 0.93–1.04; p = 0.566), diabetic nephropathy (HR: 0.99, 95% CI: 0.82–1.21; p = 0.952), or poor glycemic control (HR: 1.05, 95% CI: 0.90–1.22; p = 0.535). Similarly, histopathological findings of H. pylori infection were not significantly associated with diabetes (p = 0.311), diabetic nephropathy (p = 0.888), or poor glycemic control (p = 0.989). The findings from these large Korean cohorts indicate that there does not appear to be a role for past H. pylori infection in the development of diabetes, IGT, diabetic nephropathy, or poor glycemic control.
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Moon JS, Lee SY, Kim JH, Choi YH, Yang DW, Kang JH, Ko HM, Cho JH, Koh JT, Kim WJ, Kim MS, Kim SH. Synergistic alveolar bone resorption by diabetic advanced glycation end products and mechanical forces. J Periodontol 2019; 90:1457-1469. [PMID: 31294467 DOI: 10.1002/jper.18-0453] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 01/08/2019] [Accepted: 03/01/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND The association between diabetes mellitus (DM) and bone diseases is acknowledged. However, the mechanistic pathways leading to the alveolar bone (AB) destruction remain unclear. This study aims to elucidate the mechanical forces (MF)-induced AB destruction in DM and its underlying mechanism. METHODS In vivo periodontal tissue responses to MF were evaluated in rats with diabetes. In vitro human periodontal ligament (PDL) cells were either treated with advanced glycation end products (AGEs) alone or with AGEs and MF. RESULTS In vivo, the transcription of VEGF-A, colony stimulating factor-1 (CSF-1), and Ager was upregulated in diabetes, whereas changes in DDOST and Glo1 mRNAs were negligible. DM induced VEGF-A protein in the vascular cells of the PDL and subsequent angiogenesis, but DM itself did not induce osteoclastogenesis. MF-induced AB resorption was augmented in DM, and such augmentation was morphologically substantiated by the occasional undermining resorption as well as the frontal resorption of the AB by osteoclasts. The mRNA levels of CSF-1 and vascular endothelial growth factor (VEGF) during MF application were highly elevated in diabetes, compared with those of the normal counterparts. In vitro, AGEs treatment elevated Glut-1 and CSF-1 mRNA levels via the p38 and JNK pathways, whereas OGT and VEGF levels remained unchanged. Compressive MF especially caused upregulation of VEGF, CSF-1, and Glut-1 levels, and such upregulation was further enhanced by AGEs treatment. CONCLUSIONS Overloaded MF and AGEs metabolites may synergistically aggravate AB destruction by upregulating CSF-1 and VEGF. Therefore, regulating the compressive overloading of teeth, as well as the levels of diabetic AGEs, may prove to be an effective therapeutic modality for managing DM-induced AB destruction.
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Choi YH, Li Y, Park D, Lee J, Michael PC, Bascuñàn J, Voccio JP, Iwasa Y, Tanaka H. A Tabletop Persistent-Mode, Liquid Helium-Free 1.5-T MgB2 "Finger" MRI Magnet: Construction and Operation of a Prototype Magnet. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY : A PUBLICATION OF THE IEEE SUPERCONDUCTIVITY COMMITTEE 2019; 29:4400405. [PMID: 31156321 PMCID: PMC6538265 DOI: 10.1109/tasc.2019.2900057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This paper presents results of construction and operation of a persistent-mode, liquid-helium-free, small-scale prototype magnet for the development of a tabletop 1.5-T "finger" MRI system for osteoporosis screening. The prototype magnet, composed of 2 MgB2 coils, one superconducting joint, and a persistent-current switch (PCS) built from a portion of one coil, was wound with a one continuous ~80-m long unreacted and monofilament MgB2 wire and then reacted. The test magnet was charged successfully and generated the estimated target field of 1.75 T at 5 K with the proposed PCS operation. During initial persistent-mode, the field was slightly decayed due to the index dissipation of the joint; thereafter it sustained the persistent field of 1.7 T for 35 h. The test results validated the joint resistance of < 1.2 × 10-11 as well as the proposed approach involving the PCS coil circuit model.
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Kim HJ, Cho MJ, Yoon ES, Choi YH, Jae SY. Association Between Cardiorespiratory Fitness And Continuous Cardiometabolic Syndrome Risk Score In Korean Men. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000562122.19636.ce] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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